Eraser



- (No Model.)

G. ROBINSON.

ERASER.

No. 383,149. Patented May 22, 1888.

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UNITED STATES PATENT OFFICE- CLARK ROBINSON, OF HARTLEY, IOWA, ASSIGNOEOF ONE-HALF TO F. ALONZO BURGER, OF ST. PAUL, MINNESOTA.

ERASER.

SPECIFICATION forming part of Letters Patent No. 383,149, dated May 22,1888.

Application filed February 8, 1888. Serial No. 263,350. (No model.)

To aZZ whom it may concern.-

Be it known that I, CLARK RoBINsoN, of Hartley, in the county of OBrienand State of Iowa, have invented certain new and useful Improvements inErasers, of which the following is a specification.

My invention relates to erasers for use in 7 connection with slates andblackboards; and

it consists in the combination, with a bulb and a sponge applieddirectly to and held in place by said bulb, of a cord secured to thesponge and passing out through the bulb.

I would state here that I am aware that various devices resembling mineto a greater or less degree have before been patented, and that I makeno broad claim herein to the use of a bulb in an eraser.

In the drawings, Figure 1 is a perspective view of my improved eraser,and Fig. 2 asectional View of the same.

A indicates an elastic compressible or yielding bulb, which will be madeof rubber or similar material; and while in the drawings I haverepresented the bulb as spherical,1 do not wish to be understood aslimiting myself to that exact form, as it is obvious that it may be madein many different forms and more or less ornamental in appearance.

An opening is madein the bulb,and into this opening I force a sponge, B,as clearly shown in Figs. 1 and 2, the said sponge being of such size asto fit snugly within the opening and to be held in place solely by thepressure of the walls of the bulb-opening. By thus making the sectionalarea of the sponge greater than the diameter of the opening in the bulband forcing the spongeinto the opening, the sponge will be effectuallyprevented from dropping out. By compressing the bulb and then suddenlyreleasing it and allowing it to expand it will draw in water through thesponge. The degree to which the bulb is filled with water is a matterthat may be varied; and it is also obvious that the bulb may be firstfilled and the sponge then inserted. a

A string or cord will be secured to the eraser by tyingittothesponge andpassing i'tthrough the bulb,as shown in Fig. 2, the opposite end of thecord being fastened to a slate or blackboard.

If desired, the bulb may be made with an enlargement or made heavier atthat side opposite to the opening made to receive the sponge, so as toform a base for the eraser and cause it to always stand right side up,as indicated by dotted lines in Fig. 2.

The eraser herein described is simple and cheap, and serves the purposesfor which itis designed.

Having thus described my invention, what I claim is'- As an improvedarticle of manufacture, a

slate-cleaner comprising an elastic bulb having an opening in one wall,a sponge fitted into the opening and held therein by thepressure of thebulb, and a cord or connection secured to the inner end of the sponge,passing out through the bulb and having its end free for attachment to aslate, all substantially as shown.

In witness whereof I hereunto set my hand in the presence of twowitnesses.

CLARK ROBINSON. Witnesses:

P. H. GUNoKEL, H. W. BnssE.

